1. Field of the Invention
Exemplary embodiments of the present invention relate to a method of discriminating a region and a method of measuring a three dimensional shape by using the method of discriminating a region. More particularly, exemplary embodiments of the present invention relate to a method of discriminating an object region and a ground region and a method of measuring a three dimensional shape by using the method of discriminating between an object region and a ground region.
2. Discussion of the Background
Electronic devices have been developed to have relatively lighter weight and smaller size. Therefore, possibility of defects in these electronic devices increases and an apparatus for inspecting the defects is under development and improvement.
Recently, the technique for inspecting a three-dimensional shape becomes effective in various technical fields. For inspecting a three-dimensional shape, a coordinate measurement machine (CMM), which detects a three-dimensional shape by a contacting method, has been used. However, a non-contact method for inspecting a three-dimensional shape by using optical theories has been under development.
According to a method of measuring three dimensional shape by moiré effect, which is a representative non-contact method, a grating patterned light is irradiated onto an target object, shifting a phase of grating patterned light to measure the height of each point (x,y) of the target object in an xy plane.
In more detail, the grating patterned light is irradiated onto a measurement region (FOV: Field of View) to inspect a measurement region (ROI: Region of Interest) on which a measurement target is formed. However, when there is warpage of a substrate, a real position of the object region is not coincides with the position of CAD design, so that accuracy of measurement is lowered.
Especially, as shown in FIG. 1, when measuring a printed circuit board having a plurality of bumps for a semiconductor, measurement targets are disposed in compact. Therefore, it is very hard to discriminate an object region and a ground region (B) disposed outside of the object region.